Passengers using elevators can give calls to elevators either in elevator cars and/or in an elevator lobby. Elevator lobbies are typically provided with up/down pushbuttons, by means of which a passenger can order an elevator to the call floor and simultaneously indicate his/her travel direction. After the elevator has arrived at the call-giving floor, the passenger moves into the elevator car and indicates his/her destination floor with the pushbuttons of the car panel in the elevator car. To a constantly increasing extent so-called destination call systems are used in high-rise buildings, in which systems a passenger indicates his/her destination floor already in the elevator lobby before going into the elevator car. For giving destination calls the elevator lobbies are provided with destination operating panels.
Destination operating panels are generally provided with a so-called decimal numeric keypad and a display means. If a passenger is going e.g. to floor 24, he/she keys into the decimal numeric keypad first the number 2 and then the number 4. The destination operating panel sends the data about the call-giving floor and about the aforementioned floor 24 to the control system of the elevator system. The control system allocates the optimal elevator for the use of the passenger and transmits information about this to the call-giving panel, to the display means, on which appears e.g. the text “Elevator B”.
Since a decimal numeric keypad enables, in principle, the keying in of any floor number whatsoever, this easily results in erroneous keyings. A passenger can, for example, key in a destination call to a floor that the elevator system does not serve or the floor is temporarily locked. It is also possible that there is an access control system in use in the building, with which system the access of passengers to floors within the scope of the access control can be limited.